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arXiv · 1607.04646

Optimal and Secure Measurement Protocols for Quantum Sensor Networks

Zachary Eldredge·Michael Foss-Feig·Jonathan A. Gross·Steven L. Rolston·Alexey V. Gorshkov
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Abstract

Studies of quantum metrology have shown that the use of many-body entangled states can lead to an enhancement in sensitivity when compared to product states. In this paper, we quantify the metrological advantage of entanglement in a setting where the quantity to be measured is a linear function of parameters coupled to each qubit individually. We first generalize the Heisenberg limit to the measurement of non-local observables in a quantum network, deriving a bound based on the multi-parameter quantum Fisher information. We then propose a protocol that can make use of GHZ states or spin-squeezed states, and show that in the case of GHZ states the procedure is optimal, i.e., it saturates our bound.

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Zachary Eldredge, Michael Foss-Feig, Jonathan A. Gross, Steven L. Rolston, Alexey V. Gorshkov. 2016-07-15. Optimal and Secure Measurement Protocols for Quantum Sensor Networks. https://doi.org/10.1103/physreva.97.042337

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